FXApps

It is exciting to learn deep learning. The courses and the results are exciting and you can see it in your machine using popular libraries like Keras for Python and DeepLearning4j for Java. These libraries even have utility methods that will download famous dataset for you, you just have to copy and paste the code and run it, after training (probably a few hours on a CPU) you will have a model that is trained and ready to classify new data. I did that. I did that a lot of times. I also created small neural nets from scratch, but still, I was missing solving a problem with this technology and collect my own dataset. In this post I will share how I used DeepLearning4J to classify brazilian coins. I will try also to share how I failed a lot before getting my current 77% accuracy model. Brazilian coin for one real Collecting the data set We need a large dataset to train a neural network. They say that at least 1k images per classes . I started much less than that, about 50 ima...

It is easy to train your neural network when you get data from the web. Datasets such as ImageNet and Mnist even have utility classes to load the data, such as MnistDataSetIterator from DeepLearning4J. The problem is when you have to collect the dataset yourself. There are many ways to do that, we can try to automatize how we collect the data, but then you may have a dataset that does not reflect the real world. Right now I have to collect images form real world. I can't take pictures from the internet, that are only a few and I can't take in my house or important features won't be learned. So I created a small web application which I think that may be useful for others trying to create their own dataset. The idea is simple: You set the output directory and the possible labels in pom.xml; Then you start the application and start taking pictures with your mobile; The application then saves the images using the label as the parent directory When training yo...

If you didn't know this, now you know: calling   java.io.File.deleteOnExit can cause leaks. This is described by  Yan in his java.io.File.deleteOnExit() is evil post. You may think that you develop applications that won't create too much files and does not runs for many hours, but in an application server running for days this may be a real problem. In this post I just wanted to share how it can quickly grow your heap memory when dealing a lot of files. See the code below: Notice that the code deletes the reference to the created file object (nullify it) so it can be collected by the garbage collector. At some point the program will explodes with OutOfMemory error probably due the high amount of String created (when running with small heap). If you increase the heap and use some tool to get a heap dump of your running application you will see memory content on the *static* Linked used in DeleteOnExitHook class. We can do this in runtime by using jvisualvm (a too...

When JavaFX 2 was released I remember people looking for frameworks that would make easy to integrate JavaFX with a validation framework, a dependency injection container and other enterprise services. Currently we can integrate CDI 2.0 and Bean Validation 2.0 with a JavaFX application without the need of any external framework. In this post I will show you how to validate your javaFX screen fields using bean validation in a CDI managed application. Before talking about all these things and JavaFX I recommend you to check the following posts from this blog: Using CDI 2.0 in a JavaFX application Testing Bean Validation 2.0 Validating JavaFX controls using Bean Validation With Bean Validation 2.0 we have the automatic unwrap of JavaFX properties. Which means that if you have a field that is of type of ObservableValue so the validator implementation will be able to retrieve the actual value to perform the validation. However, JavaFX control fields are still not supported, so...

Bean Validation 2.0 is among all the new Java EE 8 good new features: In this post I will share a sample application I used to see in action the following Bean Validation 2.0 features:  List items validation Temporal validation using Java 8 Project setup Hibernate Validator is the RI for Bean Validation 2.0 and the project, being a maven or gradle project, must use the following dependencies (or later versions):  org.hibernate:hibernate-validator:6.0.2.Final and you should also add org.glassfish:javax.el:3.0.1-X   as a hibernate validator dependency, where X is the build, check the maven repository for more. This is what my pom.xml looks like: Using bean validation annotations in a bean fields To test the new annotations I used the following bean: Notice the new annotations in subscribers and in manufactureDate and expirationDate fields: subscribers : I am validating users emails, all the Strings added to this list should b...

With the CDI 2.0 release we have a container that can be used in Java SE applications! Previously if you wanted to make use of CDI 1.x in a Java SE application you had to use Weld classes, see  FXML & JavaFX—Fueled by CDI & JBoss Weld post. Adam Bien introduced the SE container in a video, see: Of course I had to try it with JavaFX so I can use CDI in some personal applications! Create the Container in a JavaFX Application By JavaFX application I mean the class that extends javafx.application.Application, which is the entry point for JavaFX apps and where the main stage can be used. To use CDI we should create the SeContainer and make sure that it create all classes managed by CDI. This should be done in the entry point Application class so we manage all the classes created from there. Once you started the container you have different ways to send the initial stage to the actual Application class, for example, you can have users to implement an interf...